[Current aspects of fungal spores allergy]

In industrialized countries the prevalence of allergic inhalant diseases is some 15-20%. More than 10% of these individuals are sensitized to fungal allergens. Many fungal spores are less than 10 microns in size, which permits penetration into the smaller airways of the lung. Bronchial provocation tests have demonstrated that fungal spores and spore extracts can cause both an early and a late phase reaction in sensitive subjects. Over 80 genera of fungi have been associated with symptoms of respiratory tract allergy. Ascomycetes, basidiomycetes and zygomycetes are the major fungal groups that contain genera known to induce and elicit allergic reactions. These groups contribute most of the spores found in air. Although ascomycetes include the greatest number of any fungal group, only a few species, such as Aspergillus fumigatus, Alternaria alternata and Cladosporium herbarum, have been investigated in a scientific manner. In recent years spores of basidiomycetes have been tested for allergenicity and some species have been determined to be allergenic, such as Calvatia cyathiformis, Ganoderma applanatum, Pleurotus ostreatus, or Psilocybe cubensis. Compared to pollen-related allergies, diagnosis of fungal allergy is often difficult. Provocative challenge with specific fungal antigens can provide a definitive diagnosis. To date, only three controlled immunotherapy trials with standardized extracts of A. alternata and C. herbarum have shown clinical efficacy. In spite of these studies, immunotherapy with fungal antigens requires further investigations. Thus, the indication for immunotherapy with fungal extracts must be judged by an experienced allergist. Apart from pharmacological management, avoiding or minimizing exposure is the front-line measure.